Air bag patents show researchers probed ways to make the devices more durable and the explosive propellant inside them more stable for decades before the Takata Corp. products designed to save lives started killing people.

The patents, some from as early as 1985, were intended to improve the ammonium nitrate propellants that help inflate the bags. They also aimed to strengthen their metal housing.

The applications provide ammunition for lawyers seeking to show the Japanese supplier could have acted sooner to head off defects linked to at least five deaths globally after air bags deployed with too much force, said Jason Turchin, a lawyer who represented a driver injured by a Takata air bag in a 2006 Chrysler sedan.

“I look at this as a road map,” said Turchin, who has two other air bag cases pending. “You’re trying to understand how this happened and why this happened, who knew what and when. Right now, plaintiffs’ lawyers don’t have a lot of answers. They need to have a way to know what questions to ask and what documents to request.”

Takata executives are being second-guessed by lawyers, U.S. regulators and members of Congress as recall numbers climb beyond 10 million involving at least 10 global automakers. Takata said last week it still doesn’t fully understand the root cause of the failures, which have also injured hundreds of people. The Tokyo-based company has said it has been aware since 2005 of a flaw in air bags made as early as 2000.

Risks known

A Bloomberg News review of the patents studied by Turchin as well as several others shows that Takata researchers have been aware of the instability of ammonium nitrate and other risks for more than a dozen years.

Turchin cites two patents, one from 1985 and another from 1989, that address the possibility air bag housings can degrade at high temperatures and otherwise be at risk of rupturing or breaking apart. At least seven applications from Takata cite those two patents, according to a patent search by Innography Inc., an Austin, Texas-based maker of software to analyze patent portfolios.

Honda Motor Co., Toyota Motor Corp. and Ford Motor Co. were among automakers last week that agreed to seek independent testing of Takata air bags and expanded recalls based on evidence showing new risks for models not included in earlier safety actions. Honda expanded U.S. recalls by 2.6 million, to about 5.4 million, for driver’s side air bags.

Flawed manufacturing

A Takata executive told Congress last week that a flawed manufacturing process for the ammonium nitrate pellets ignited to create the gas needed to fill the air bags meant the mixture exploded with too much force. That caused the canister meant to contain the explosion to break into pieces and strike passengers, the company said. The company has also said moisture entering the air bag inflator as well as the age of the equipment may be factors in some of the failures.

Takata and all safety companies need to be able to seek solutions to possible shortfalls in safety equipment without fear of retaliation if the industry is going to advance, said Douglas Campbell, president of the Automotive Safety Council, an industry advocacy group for more than 30 safety-equipment makers including Takata.

Previous generations of air bags used a much more toxic compound as the explosive to inflate the bag and the equipment was activated using a metal ball rolling in a tube based on the crash severity, he said. Today’s bags use sophisticated computer sensors, he said. U.S. data shows 37,000 people were saved by the technology from 1986 to 2012.

Propellant risks

Manufacturers have used various propellants over the years to achieve safe and effective performance in air-bag inflators, and each type of propellant requires a balance of potential risks and benefits, said Alby Berman, a Takata spokesman.

Ammonium nitrate-based propellant burns cleaner and is more efficient, meaning air bag inflators can be smaller and lighter, he said in an email statement. It is also more stable than other compounds, making it safer to handle during the manufacturing process.

“Takata has always understood the effects that moisture may have on the combustion characteristics of ammonium nitrate, but phase stabilized ammonium nitrate based-propellant is safe and effective for use in airbag inflators when properly engineered and manufactured,” Berman said.

Defendants may be able to limit the use of the patent applications as evidence in trials under the “subsequent remedial measures” rule in federal courts, said Carl Tobias, a University of Richmond law professor. That rule established that encouraging improvements is a matter of public policy, Tobias said in a phone interview. Trying to fix a problem is not an admission of liability, according to this rule.

Plaintiffs’ leverage

Tobias said the rule does not block use by plaintiffs’ lawyers during or before trial. “It depends on how it’s characterized,” he said.

Plaintiffs’ attorneys can use the patent applications as leverage in pushing settlements and to develop other evidence, Tobias said. The patents identify witnesses to question, he said.

Kendall Few, a Greenville, South Carolina, plaintiffs’ lawyer, has used patent searches for years as evidence to support product-defect claims against automakers and suppliers. Since most patent applications cover improvements to existing know-how, they often identify flaws in products that are on the market, he said.

While the weight of the argument varies from judge to judge, few have blocked him from using such evidence, he said.

Most cases never go to trial and the patent applications are used in early stages, including depositions, as indications a company knew of possible design flaws, he said.

Takata patents

Takata patents from 2001 described the potential instability of ammonium nitrate. Patents from 2006, 2007 and 2009 discussed the risk of moisture making the explosive unstable, Turchin said.

A patent application this year described how even normally operating air bags can inflate with a quarter more force at temperatures at the top of the operating range, or 185 degrees Fahrenheit (85 degrees Celsius), than they do at 73 degrees. Another filing from this year discusses the risk to ammonium nitrate in extreme ranges of temperatures, Turchin said.

“Once they determined there was any issue whatsoever, they should have informed the public to get the air bags replaced,” Turchin said. “What we learned from the patent search was that their employees were aware of several issues with the air bags and didn’t share that with the public.”

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
By subscribing, you can help us get the story right.